Much is said about the subject of bodybuilding bulking. Two primary bulking camps exist: clean and dirty. Clean bodybuilding bulkers believe that you should eat an excess amount of calories, but they should come from healthy sources. Dirty bulkers believe that a calorie is a calorie, and regardless of its source – healthy or junk food – you will pack on muscle.

Which camp is right? Both.

The human body doesn’t seem to care where your calories come from, and long as they come. Bulk with clean foods, and you will pack on muscle. Bulk with dirty foods, and you will pack on muscle. When using the Bulldozer Bulking System, eat foods that suit your needs. If you want to bulk 100% clean, by all means do so. If you want cheeseburgers and pizza, start warming up your pie hole.

But this isn’t the end of the story. There is more to bodybuilding bulking then just mere calories. The most important aspect to bulking is timing and cycles.

The Cycle. The Bulldozer Bulking System is simple. You bulk for 2 weeks, then cut for 2 weeks. But this is not merely a haphazard system, thrown together in an effort to be unique and stand out from the crowd. Science backs up the Bulldozer Bulking System.

In study after study, science reveals that the human body is equipped to handle an excessive caloric intake for short periods of time. During shorter bulking periods, the body packs on muscle mass, becoming extremely anabolic.

The Rochester Study. The University of Rochester School of Medicine and Dentistry studied the hormonal response to mixed-diet bulking. Results revealed a significant boost in anabolic drive. Participants experienced rocketing levels of insulin, testosterone, and IGF-1, and experienced a significant increase in muscle mass. As in the “12 Day Study”, resistance training was not involved.

The Short Term Study. In the study, Short-term, mixed-diet overfeeding in man: no evidence for “luxuskonsumption”, following a 13 day caloric maintenance period, 5 male subjects ate bulking diets for a 9 days period. During this time, subjects gained an average of 7.04 pounds. 3.1 pounds of this gain was muscle mass. (Please note that this bulk followed a maintenance period, and not a cut)

Protein Intake and Bulking. So, does it matter what you eat during a bulk? Do you need to increase protein intake dramatically? The answer is no. A study by Chiang and Huang revealed that an overall caloric intake was the key to boosting the body’s nitrogen balance.

In this study, participants were placed on a fixed protein intake diet. When daily caloric levels were increased by 15%, nitrogen retention levels tripled. When subjects consumed 30% more calories, nitrogen retention levels spiked to nearly 5 times the starting level.

So, when bulking, it is not necessary to eat more protein. Upping your protein levels during a bulk is still a suitable means of packing on muscle mass, but the body doesn’t really care where you get the extra calories from. During a bulk, the body responds to a bag of Doritos in the same way it responds to 5 extra chicken breasts.

Why a 2 Week Bulk? Why the need to limit a bulk to 2 weeks? In the “12 Day Study“, spiked insulin, testosterone, and IGF-1 levels reached a summit after 14 days, and began to decrease.

Simply put…the body is not built to process bulking for periods longer then 2 weeks. It can handle short term caloric increases extremely well, but eventually, the anabolic benefits from bulking disappear.

Why a 2 Week Cut? Why follow a bulk with a cut? Why not just slide back into maintenance mode and eat normal calorie levels? In most cases, 2 week bulking diets produce more muscle gain then fat gain. And during short term cutting periods, the body loses more fat then muscle.

Of course, some of the muscle mass added during a bulk with be lost during the cut, but cycling between bulking and cutting makes it much easier to exit a long term bulk without having to shed 20 to 40 pounds of fat. Again, after 2 weeks of bulking, the anabolic benefits of excess calories decrease.

Bulldozer Bodybuilding Bulking Diet. Cutting through the studies and statistics, here is the bottom line…